Erdem x H&M finally launches on Thursday, November 2, and past designer collaborations with the Swedish retailer suggest there will be a mega-frenzy surrounding the collection.

Consider several of the more recent collabs. In 2013, the San Francisco queue for the Isabel Marant x H&M collection started at 7 pm the night before the launch. In 2014 and 2015, the Alexander Wang x H&M and Balmain x H&M lines started at 11 am the day before. While the Kenzo collection last year was a rare miss for the retailer, there's a ton of buzz surrounding the Erdem pieces. (It doesn't hurt that Kate Middleton has worn the designer multiple times.)

Here's everything you know about shopping Erdem x H&M in San Francisco.

Location

In recent years, H&M has released it fall designer collections at both the Union Square and Westfield San Francisco Centre stores, but a rep for the brand tells Rockyt that the collection will only be available at 150 Powell Street this year. That means you can expect an even crazier line than usual.

Waiting

To put the timing in perspective, I arrived at 7:30 am in 2014 for the Alexander Wang launch, and I was in the fifth entry group—somewhere around number 150 in line. The following year, I arrived at 6 am for the Balmain launch, and I was in the 10th timed entry group—around number 300 in line. Both years, shoppers were split between the Union Square and Westfield stores. This year, the collection is only at one store. If you want a shot at the best pieces, I suggest arriving no later than 5 am. The store will open at 8 am on Thursday.

[Update, 11/2/17: The first person in line arrived at 2 am. At 6:25, there were only 25 people here. At 6:45 am, the line started wrapping onto O’Farrell.]

H&M uses wristbands to keep the line under control, with shoppers traditionally being admitted in groups of 30. The wristband is critical. It doesn't matter if you stand in line all night; if you miss the wristband handout while you're taking a bathroom break, you'll be SOL. (I've seen it happen.) Starting around 6:30/6:45 am, I wouldn't recommend leaving the line until you have a wristband.

Once admitted, you have 15 minutes to shop before your group is cleared to the dressing room. It will be a madhouse inside the store, so that is definitely not the time to browse the collection for the first time. Review all the pieces and prices on the H&M website before you queue up.

Surviving

There is generally a sense of camaraderie among the long-time line standers, so you don't have to physically remain for the entire day/night once you arrive. Past early-bird line standers have told me that they scampered to the Starbucks across the street, (201 Powell Street), for snacks, coffee, and bathroom breaks. While that may work for a while, Starbucks has placed an "Out of Order" sign on its bathroom several times during the early morning hours on launch days after too many people retreated into the coffee shop for bathroom breaks.

Beyond the Starbucks, other nearby 24-hour eatery options include Pinecrest Diner (401 Geary Street) and Lori's Diner (500 Sutter Street). Like most restaurants, bathroom privileges are reserved for customers, but they'll probably let you make a purchase to gain access to the bathroom. If you're determined to reserve all of your spending power for actual clothing purchases, think about trying nearby hotel lobby restrooms. Hotel Nikko is close (222 Mason Street), as is the Westin St. Francis (335 Powell Street).

In addition to the bathroom situation, you should also be thinking about the climate. Low temperatures in the city on Wednesday and Thursday are predicted to be around 50 degrees. Wear layers, bring a jacket, and consider packing hand warmers as well. (It sounds like overkill, but you'll thank me later.) If you're going to wait for an extended period of time, bring a chair, a book or magazines or knitting to keep you occupied, and a backup battery charger (and cord!) for your phone.

Keeping Your Job

There are always news crews covering the line. If you want to call in sick so you can shop instead of reporting to your job, bring a disguise. A hat. Sunglasses. Something to shield your face. Every year, there's some a sucker who waits in line for three hours only to skitter away empty-handed when ABC7 shows up. Don't let it be you.

Purchasing

H&M usually limits the number of units a customer may purchase to only one piece per product. (That means you could buy one of the beaded dresses, one of the Cher Horowitz skirts, one pair of the floral combat boots, etc.) You can return your purchases for a refund within 6 days, or for store credit at the current selling price after that.

[Update, 11/2/17: Purchase limits and return deadlines have been updated with this year’s rules.]

Updates

I will be on-site and line-blogging the Erdem x H&M scene in San Francisco on Thursday morning. You can follow along on Twitter at @HelloRockyt, or right here on www.Rockyt.style. If you have a tip to share, tweet me (@hellorockyt) or email me at rockytstyle@gmail.com.

How to Make Your Erdem x H&M Dreams Come True in SF